WR450 jetting with a PMB Insert

7 replies to this topic
  • foursmoke

Posted May 20, 2003 - 03:42 PM


I currantly have a 160 main, 48 pilot, 72 starter and a Zip-Ty-fuel screw out 2 turns with an open pipe. I ride between sea level- 1000' I am putting on a PMB Insert and I would like to know how much leaner I must go with my jetting. I'm not positive it is perfect at the moment but it is pretty close. If I pull in the hot start lever with current jetting it has lean popping at idle if that helps. It seems to run well now but hesitates slightly when you wack open the throttle. I have not inspected the plug. Thanks!

Smoke :)

  • foursmoke

Posted May 21, 2003 - 01:08 PM


C'mon! Someone can at least waste 2 sentences on me to get me started. :D I've never been ignored by you guys before. :D This sucks!!!!!!! :D :D

Smoke :)

  • Indy_WR450

Posted May 21, 2003 - 01:23 PM


155 main,needle in clip #4 from top, 45 pilot, 65 or 62 starter, try 1.5 turns as a start. Worked well for me in the warmer weather with the stock pipe and baha insert. :)

  • ddialogue

Posted May 21, 2003 - 05:56 PM


Without the insert I was at a 155 main, stock needle in the 5th position, 45 pilot, stock starter jet (unknown what it is) and 2 turns out on the pilot air screw. With the PMB insert I have reverted almost completely back to stock jetting except for the main: 155 main, stock needle in the 4th position, 42 pilot, stock starter jet (unknown what it is..didn't I already say that??) and 1 and 1/2 turns out on the pilot air screw. I'm at 2700ft. Starts easily; runs strong; never a fouled plug.

I love this bike...

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  • foursmoke

Posted May 21, 2003 - 06:35 PM


Thanks alot guys! I have the main & pilot jets but only have a 72 starter and the stock one. Are the jets on back order? I had heard that the jets for the 450's are on back order until July :D. I thought by getting the PMB I could avoid dealing with back order issues and quiet down the bike at the same time :). Will I loose alot by running an insert :D? I have been running an open pipe for 3 months.

Smoke :D

  • Desracer

Posted May 21, 2003 - 07:47 PM


Jets are easy to get. Try your Honda dealer also, a good parts department will have a selection of jets. Im running the 155 and 48 the rest is stock. Good luck!

  • ddialogue

Posted May 22, 2003 - 03:21 AM


My impressions from going fully uncorked to a PMB insert was this:
1) VERY quiet
2) Small loss of bottom end power
3) I can hear all the engine noise now :D

It took a bit of getting used to how the power comes on with the insert. Seems like I have to rev the bike just a hair more than I did without any insert at all. I did notice that I related the noise to the power. When I no longer had the noise it felt as if I had lost the power when in reality the power was still there...it just didn't sound like it. :)

Remember, jetting is very important when using these inserts.

  • bbarer

Posted May 22, 2003 - 10:34 AM


Foursmoke, I am right down the street from you in Taunton. Iwent up to a 155 without an insert and then back to stock jetting when I got the PMB insert. Bike runs awesome and appears to be jetted perfectly. Only a slight power drop from the open pipe but with a dramatic drop in noise. I can't tell you where I have the fuel screw as I spent so much time messing with it before I got it right I never attempted to screw it back in to see where I am at.

We should probably try and link up some day for a ride.


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